Biodiversity Net Gain

The suitability of habitat improvements/actions are based upon an appropriate ecological survey and inspection of the land. Design decisions are made in conjunction with locally relevant evidence, expert input and guidance, ensuring the interventions are realistic and deliverable within the project timeframe.
We use the official defra Biodiversity Metric to calculate how a change in land management will enhance the biodiversity value of a site, following this process:

  1. Initial desktop assessment to find ownership, location, type, size, condition and strategic significance
  2. Baseline using the Biodiversity Metric survey
  3. Environmental management options to arrive at Biodiversity Net Gain measured in Units
  4. Draw-up a Conservation Covenant or s.106 agreement to ensure 30-year validity
  5. Create a Management Plan for monitoring and reporting the project
  6. Establishment of biodiversity uplift Banking
  7. Marketed through our agency
  8. Recording of biodiversity sites on the Government's Biodiversity Net Gain Registry

Environmental enhancement is reported through three distinct Biodiversity Unit BU types, further divided and recorded within our registry as:

  • Area - species rich grassland, scrubland or woodland
  • Linear - hedge or line of trees
  • Linear - watercourse

We can advise on matching you to a site that suits your requirements and location.

Carbon Codes

Addisons are Project Developers registered with the IHS Markit Environmental Registry for Woodland Carbon Code projects. The robust carbon standard established to gain access to private funding and the Government’s Woodland Carbon Guarantee.
We advise on establishment, maintenance and access to the Carbon market via the Woodland Carbon Unit (WCU) and Pending Issuance Unit (PIU) offered by woodland creation - an added dimension to land management and private investment opportunities.

Peatland Carbon - voluntary code similar to the Woodland Carbon Code.

Nutrient Credits

Nutrient pollution is a huge environmental issue for our water ecosystem. In freshwater habitats and estuaries, increased levels of nutrients (especially nitrogen and phosphorus) can speed up the growth of certain plants - a process called ‘eutrophication’ - and it is damaging protected sites resulting in some classified as being in ‘unfavourable condition’.

The sources of nutrients generally include sewage treatment works, septic tanks, livestock, arable farming and industrial processes. Where sites are already in unfavourable (poor) condition, extra wastewater from overnight accommodation including new homes, student accommodation, care homes, tourism attractions and accommodation developments can exacerbate this. Other applications will be considered on their individual merits.

By designing suitable mitigation measures for a development, additional nutrient load can be avoided. This approach is called ‘nutrient neutrality’. It essentially allows developments to progress without impacting on the condition of the important wildlife and/or protected sites.

Nutrient Nutrality - Nitrate and Phosphate credits - may be provided by private landowners establishing wetlands and woodlands - subject to Natural England ratification.

The map below shows the Tees Catchment area that feeds the Teesmouth and Cleveland Coast Special Protection Area and RAMSAR site. We are currently looking for donor Nutrient Sites sites within this catchment area to mitigate the excess nitrogen levels within the protected site.

Natural Capital elements

  • Are offered subject to documentation / contract / submission.
  • We also only act on a subject to contract / documentation basis when buying units / credits for our clients and do not enter into oral contracts.
  • Any such verbal comments or statements made by Addisons Chartered Surveyors during the consultation process or otherwise cannot be relied upon unless such advice is provided in writing following receipt of written instructions for Addisons Chartered Surveyors to provide such advice. Any such oral comments or statements do not form part of our brokerage instructions or any transfer contracts.
  • Any quotes, prices, rates or advice given by Addisons Chartered Surveyors may be subject to change by future Government reforms.


Addisons Surveyors LLP

David Hall
Fellow of the Royal Geographical Society
Geographical Information Systems MSc
Natural Resource Management MSc